The present invention relates to a lens tube guide frame for use in a lens tube retractable type camera, which is capable of establishing the distance between the lens and the film surface to a high degree of accuracy and can be assembled easily.
In a conventional lens tube retractable type camera, as shown in FIG. 1, a lens tube guide frame 3 is inserted in a concave light-tight box 12 formed in the body 1 of a camera and is attached to the body 1 by a screw 4. The length of such a lens tube guide frame 3 is A film receiving plate 5 is held in place on the rear end surface 3a of the lens tube guide frame 3 by four screws 41, and a lens tube 2 is inserted inside the frame 3. The distance l.sub.5 between the front end surface 3b of the frame 3 and the film receiving plate 5 is adjusted while measuring the distance l.sub.5 by a jig, with a washer 6 held between the rear end surface 3a and the film receiving plate 5, so that a predetermined space is maintained between the lens and the film surface when the lens tube guide frame 3 is assembled.
A conventional lens tube guide frame of the type just described has the following shortcomings: The assembly process is complicated and long. After the basic assembly of the components, a lot of time is required for adjusting the lens tube guide frame. The assembling efficiency is poor. Too many parts are necessary. The inferior ratio of the lens tube guide frame is high in production process thereof, with the scattering of size accuracy of each part multiplied. And it is difficult to maintain the relative position of the lens and the film surface with high accuracy.